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Swiss researchers develop convoy system for both CAVs and manually-driven cars

In what is being seen as a key step in the shift toward widespread autonomous driving, which is expected to be achieved by 2030, researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL) have developed an algorithm for automated vehicles to operate in traffic alongside manually-driven vehicles.

The transition from a handful of connected and autonomous vehicles (CAVs) today, to a true smart system used by automated and manually-driven models over the next 13 years, is seen as a major challenge. Researchers from the European AutoNet2030 project believe it can be achieved by combining driving assistance technologies and inter-vehicle communications. They have recently shown that it is possible for vehicles with or without drivers to operate in high-speed, multi-lane traffic autonomously under real-life conditions. EPFL’s contribution to the project came in the form of a cooperative maneuvering control algorithm.

One option under study is to have automated vehicles travel in convoys, which has been successfully tested in several pilots worldwide. The only problem is that this type of convoy behaves as a discrete block which, above a given number of vehicles, becomes increasingly difficult to manage. The AutoNet2030 researchers came up with another solution: a cooperative and distributed system. Each connected vehicle communicates directly with other vehicles in the immediate vicinity, and they adjust their speed and position independently of each other, reconfiguring when another vehicle joins the group.

Convoys are managed using control software based on an algorithm developed by EPFL’s Distributed Intelligent Systems and Algorithms Laboratory (DISAL). The algorithm uses information that it receives from the agents’ sensors to guide the convoy’s movements in real time. The convoy automatically and constantly reorganizes when, for example, another vehicle joins or leaves it, it changes lanes, or it adapts to target speeds. The DISAL researchers began by managing robots on simulators, before moving on to real miniature robots, and then to cars on simulators. Finally, as part of the AutoNet2030 project, they managed to get real vehicles on the road.

The final demonstration took place at the end of October 2016 on the AstaZero test track in southern Sweden. Three vehicles were used: an automated truck and car and, a key aspect of the project, a networked though manually-driven car. The researchers equipped the non-automated car with GPS and laser sensors, and a human-machine interface allowing the driver to follow instructions on joining the convoy.

“It may not seem so impressive with only three cars, but for the first time we were able to validate what we had achieved in the simulation. And the number of vehicles in the convoy has no impact on the complexity of the control mechanism,” said Alcherio Martinoli, DISAL head.

Guillaume Jornod, the EPFL scientist who ran the trials, noted, “This is a proof of concept. We are hoping that car makers will find cheaper solutions for converting legacy vehicles, and deploy and improve this multi-lane convoy system for heterogeneous vehicles.”